Air pumping centrifugal pump



July 19, 1932. A. w. BuRKs AIR PUMPING CENTRIFUGAL PUMP 4 sheets-sheet 2Filed Feb. e, 1930 awr/M140 July I9, 1932. A. W. BURKS AIR PUMPINGCENTRIFUGAL PUMP 4 Sheets-Sheet` 3 Filed Feb. 5. 1930 July 19, 1932. A.w. BuRKs. 1,867,652

AIR PUMPING CENTRIFUGAL Puna;

' Filed Febf. 1930 I 4 Sheets-Sheet 4 Patented July 19, 193.2 i

ARTHUR W. BURKS, F DECATUR, ILLINOIS am rumena@ cENTnIrUeaL PuurApplication led February 6, 1930. Serial No. 426,358.

The present invention relates to rotary pumps and has as an object theprovision of an improved rotary pump of the centrifugal type, althoughcertain features of the inven- 5 tion are applicable to pumps of othertypes.

A more particular object of the invention is to provide a centrifugalpump which is adapted to pump upon either gas or liquid.

A. still further object of the invention is to provide a centrifugaltype pump which is self-priming and which is not only novel inconstruction, but involves a new method of operation. A

The invention, therefore, seeks to provide a new and improved pumpconstruction, and

a novel method of operating a centrifugal pump, the method having to doprimarily with the pumping of air and the automatic priming of the pump.

With respect to the pump construction, the invention relates to theformation of the fluid'channel or raceway into and through which theHuid is impelled; to the rotor conf struction; to the means for adapting.the pump for operation upon air; and to means for making the pumpself-priming.

' The invention has as another object a centrifugal pump`whichwi1loperate effectively upon air, and which will, therefore, serve as an aircompressor, as Well as a liquid pump.

The invention also has as an object a vcentrifugal pump which isself-priming so that it will automatically evacuate the supply line whenthe pumping operation is initiated and which will automatically removeany air which lls the pumping chamber during the pumping operation andths automatically insures uninterrupted continuance of liquid 4Upumping.

The present invention involves a method of operation in which Huid issupplied to the rotor whenever the latter tends to become air bound andin which this supply of liquid is i utilized for the purpose ofwithdrawing the air from the pump at the point of'supply and forseparating and discharging the air withdrawn.

The method also involves means for maintaining at the point of suchliquid supply a whirling body of liquid or a whirlpool which separatesthe removed air by centrifugal actlon. f

For this purpose, the rotor is provided with a series of buckets whichare engaged by the liquid whirlpool to displace air from the bucketsinto the whirlpool. The buckets are in communication with air in theimpeller chamber, and also, preferably, in communi-v cation with thepump inlet so that air may be drawn therethrough to the buckets.

In the operation ofthe pump, the water which enters the buckets todisplace the air is returned to the whirlpool, at least as long as airis being pumped. This return is effeted through the main fluid channelor raceway of the pump and the channel outlet. In other words, thewhirlpool is always maintained sufficiently filled with yliquid duringthe air pumping phase and any liquid carried therefrom by the buckets isreturned by means other than the buckets. The buckets are, therefore,free to discharge any water they carry from the whirlpool and to befilled with air before they again reach the whirlpool.

. I have also discovered that the operation of a centrifugal pump may besubstantially improved by providing a novel form of fluid channel orracewayu into which the impeller may centrifuga-Hy discharge. Theraceway,

`whichfollows the periphery of the rotor for a substantial portion `ofthe rotor circumference is relatively narrow, and not substantiallywider than the rotor at its periphery, particularly at the entrancethroat. I-have discovered that if such a raceway is maintainedrelativelv narrow and has fiat side walls which may be spaced apart agreater distance `radially outwardlyfrom the rotor than at the -rotorperiphery, there is a substantialreduction in the formation of eddycurrents, and furthermore, a marked increase in the pressure developedbv the pump.

The foregoing and other features of the invention willy become clearerin connection with a detailed description of certain preferredembodiments disclosed in the accompanying drawings.

In these drawings:

Figure 1 is a side elevational view with parts broken away.

Figure 2 is a vertical section on the line 2 2 of Figure 1.

Figure 3 is a horizontal section on the line 3 3 of Figure 1.

Figure 4 is an end elevational view of a modified form, parts beingbroken away to show the internal contruction.

Figure 5 isa vertical section on the line 5 5 of Figure 4, looking inthe direction of the arrows.

Figure 6 is a horizontal section on the line 6 6 of Figure 4. f

Figure 7 is a side elevational view of another modified form, with partsbeing broken away.

Figure 8 is a vertical sectional view on the line 8 8 of Figure 7.

Figure 9 is a top plan of the pump shown in Figure 7.

Figure 10 is a fragmentary sectional view showing a modified from ofraceway.

Figure 11 is a side elevational view of another form, with parts beingbroken away.

Figure 12 is a vertical sectional view on the line 12-12 of Figure 11.

Figure 13 is a plan view partly broken away.

Fi re 14 is a fragmentary sectional view i showing a modified form ofrotor construction, which may be used in lieu of that shown in Figures11 and 12.

Figure 15 is an edge view of the rotor shown in Figure 14, partly brokenaway.

Figure 16 is a fragmentary sectional view showing the internalconstruction of the impeller employed in all of the pumps.

Referring to Figures 1, 2 and 3, the pump comprises a casing having twosections 10, 11

w secured together as by bolts 12. The casing has a substantiallycentral hollowl boss 13 which serves as an inlet and is connected with asupply line 14. The interior of the boss is enlarged as at 15 to receivewith substantial clearance, a hollow hub 16 of a centrifugal impeller orrotor 17. The interior of the rotor, as best shown in Fig. 16, isdivided by a plurality of curved circumferentially directed webs 19 intoa plurality of peripherally directed passages leading from the hollowhub 16, the passages being arranged between the opposite lateral faces20, 21 of the rotor. At its periphery 22, the rotor discharges into afluid channel or raceway 23 having at the impeller periphery an entrancethroat 24 which is of substantially the width of the rotor at itsperiphery. The throat faces the rotor to receive vfluid centrifugallydischarged therefrom into the channel 23, which is relatively narrow,between the flat side walls 25, 26. These walls may be formed so thatthe channel/increases slightly in width from the throat 24 radiallyoutwardly from the rotor, as by inclining the wall 26 (Fig. 3). In someinstances, it may be prefer- Y rotor in a counterclockwise direction(Fig. 1),

and. as will be evident from a comparison of the radial dimension of theraceway at opposite sides of the rotor in Fig. 3. Fluid drawn into therotor as the latter is revolved byr means of rotor shaft 30, on which itis fixedly mounted, will be centrifugally discharged into the raceway orchannel 23, and will pass through this channel to the outlet 27 where itenters tangentially the bottom of a chamber 31 which is substantiallycircular in horizontal cross section for a, purpose to be explained.This chamber has a bottom 31 which maybe provided with a drain plug 32and is in communication with a whirlpool set up by a series of bucketsdisposed on the rotor, and which will now be described.

The rotor has, preferably on a lateral face, a plurality ofbuckets 33formed by a circular series of blades 34 disposed on a lateral face andradially inwardly from the rotor periphery. These buckets are disposedso as to receive air, and in the present instance, this is accomplishedby placing thesame in communication with the inlet by the space 35between the rotor hub and the casing por'- tions 13. The buckets travelin a circular channel 36 formed in the casing and are in communicationwith a body of liquid, which in the `present instance, is maintained inthe chamber 31. For this purpose, the chamber 31is provided with anopening 37 in its wall, through which the buckets as they pass thechamber may communicate with the interior of the latter. In the formshown, the buckets project into the chamber (Fig. 3) since they projectlaterally from the wall of the rotor. As the buckets pass the chamber,they tend to maintain in the latter a liquid air separating whirlpool,the liquid of which engages the buckets and displaces therefrom into thewhirlpool air contained in the buckets. This air is separated by thecentrifugal action of the whirlpool and passes upwardly from the chamber31 through the discharge pipe 38 which (Fig. 3.) is of considerablylesser diameter than chamber 31.

It will be apparent that in the form being described, the liquidwhirlpool in chamber 3l water, as -the rotor passes from the opening 37in counter-clockwise direction, as illustrated by the arrow 28 (Fig. 1)will pass outwardly into the channel 23 through the space 39 between thewall 21 of the rotor and the casing section 10, 11. This water passesaround the channel and is discharged again through outlet 27 into thechamber 31, and

since the lower end of the latter is in communication with the whirlpoolformed by the buckets 37 the water may again engage the buckets.

It will be evident, therefore, that there is a constant circulation ofwater from the whirlpool within chamber 31 around the raceway and backto the chamber, due to the fact that as air is displaced from-buckets33,

the water which has effected the displacing action, must be carried awayby the buckets.

This water is maintained at a minimum and is returned to the .Whirlpoolby means other than the buckets, namely, through the raceway 23 andchannel outlet 27.

Due to the fact that the buckets are in communication with air andpromptly discharge into the raceway any water they take from the liquidwhirlpool, it is possible for the pump to evacuate effectively its ownsupply line, provided when the operation of the same is initiated, asuiiicient quantity of water is placed in the chamber 31, for examplethrough the discharge 38, to set up the air separating whirlpool in ahorizontal plane which will engage the buckets and displace therefromair which enters the buckets from the inlet. After the line isevacuated, the pump will continue to draw water, and the same will becentrifugally impelled by the rotor into the raceway,v although somewater may be pumped by the buckets 37, and this is discharged into thechamber 31 as the buckets enter the same.

It will be found that during both the air pumping period and the liquidpumping period a whirlpool is maintained in chamber 31, and thiswhirlpool will tend to separate from the water any air which may becombined therewith, the air passing from the whirlpool at its center andupwardly through the discharge pipe 38.

When it is desired to pump air alone, it is simply necessary that thechamber 31 contain water in suiicient quantity to form a liquidwhirlpool and then the supply line maybe opened to the air in anysuitable manner so that the pump will draw air therethrough in themanner described.

As will be observed, the chamber 31 is pro-` vided with a` spiralpassage 42, which leads from a point 43 in a. horizontal plane adjacentthe top of the chamber downwardly to a point 44 adjacent the outlet 27.This passage serves to direct the liquid of the whirlpool adjacent itsouterrim from the upper portion of the whirlpool to a lower portionthereof so as to insure return tothe body of the whirlpool from adjacentits up er portion, water which has been freed om air by the centrifugalaction. This feature of the pump is more fully described and is claimedin my co-pending application, Serial N o. 425,868, filed February 4,1930.

It has been found that the flat cross sectional shape of the channel 23(Figs. 2 and 10) materially improves the operation of the pump, and thatwater is discharged from the impeller into the channel substantiallywithout the formation of eddy currents.` Comparative tests indicate thatthis form of raceway adds considerably to the efficiency of acentrifugal pump. The raceway increases in radial dimensions, asillustrated by the dotted lines in Fig. 1 around the'pump and may beeither of the substantially wedgeshaped cross sectional form shown inthese figures, or of the uniform cross sectional width shown in Fig. 10.Referring to Figures 4, 5 and 6, the roto is disposed between casingsections 51, 52, the latter having a central opening 53 closed by aplate 54 maintained in position on section 52 by a marginal rib 55 whichiits around a 'flange 56 surrounding the opening 53. lThe rotor shaft 57is mounted in a bearing 58 positioned centrally of the plate 54, and theroto`r is of the same construction as the rotor of Figs. 1, 2 and 3. Ithas the internal dis-` charge or impelling passages (Fig. 16) whichcommunicate with a hollow hub 59 arranged within the inlet boss 51', thelatter having a supply connection 52. The rotor also has the lateralseries of buckets 60 formed between blades 61, these blades beinglongitudinally arcuate as shown in Fig. 1, and in communication throughan opening 62 with achamber 63.

The opening 62 is of substantial length longitudinally `of chamber 63and has arcuate edges 64, 65 which follow for a substantial distance thepath of movement of the blades 61. As the blades 61 pass the opening,they communicate with the chamber (Fig. 6) and in the present instanceproject thereinto, to set up an air separating whirlpool, the liquid ofwhich engages the buckets and serves to displace airtherefrom into thewhirlpool.

The buckets may draw air through the space 66 between the rotor and thewall of the casing section 51, this space leading from the buckets tothe inlet boss and thus being in communication with the inlet connection52. Water which is carried od' from the chamber 61 by the buckets willbe discharged outwardly by the buckets after they leave the opening 62into the channel 67 which corresponds in formation and function to thechannel 23 described in connection with the form of Figures 1, 2 and 3.This channel directs the fluid through an outlet 68 and tangentiallyinto a chamber 69 wherein a .whirlpool is set up by the tangentialdischarges. The chamber 69 is in communication with the chamber 63, and,in the form shown, forms the lower end of the latter. It may have in itsbottom wall a drain plug 71, and leads to a discharge connection 72, inthe present instance, through the chamber 63.

The operation of this pump is very similar to the pump of Figs. 1, 2 and3. It w1ll be understood that the 'liquid which enters inlet 51 iscentrifugally discharged by the impeller into the raceway 67, throughwhich it passes to be tangentially discharged into chamber 69. Ifconsiderable air is entering the pump through inlet 51', the same willenter the buckets 60, and as the latter pass opening 62, the whirlpoolin chamber 63 set up by the action of the buckets, will displace intothe whirlpool the air in the buckets, the air being thereafter separatedby the centrifugal 'action of the whirlpool and being discharged throughoutlet connection 7 2. It will be understood, of course, that this airdisplacing action will not continue after there is sufficient airand'liquid in the pump to fill the buckets.

To initiate operation of the pump so that it may evacuate its line, itis simply necessary to place in the chamber 63 a sufficient amount ofwater to form a liquid whirlpool under the action of the buckets 60.Although some water is carried off from the whirlpool by the buckets asthey pass opening 60, it is returned to the whirlpool through theraceway 67 and outlet 68. In other Words, this water leaves the buckets60 before the latter return filled with air to the opening 62. Wheneverthe pump chamber tends to become air filled, the air will beautomatically removed in this manner, and the air withdrawn from thebuckets is separated from the lwater in the Whirlpool by the centrifugalaction of the latter and then discharged. The construction also enablesthe pump to be utilized as an air pump or compressor, and for thispurpose it is simply necessary to place the supply connection 62 incommunication with the air and to fill the chamber 63 with liquid.

Although the raceway is shown of substantially Wedge-shapedconstruction, it will be understood that the same may be of the formillustrated in Fig. l() or of any other preferred form. l

Referring to Figs. 7, 8 and 9, the pump shown comprises casing sections73, 74 having therebetween a peripheral section 75 containing a raceway76 surrounding the impeller 77, the internal construction of the latterbeing the same as illustrated in Fig. 16.

The raceway 76 in the present instance is shown as of substantiallycircular cross section, although it may be of the form shown in Figs. 3and 10. It has an entrance throat formed between a lip 76 and anopposite wall 7 8, through which the impeller peripherally dischargesinto the channel which surrounds the impeller.

The rotor impeller has an axially disopsed hollow hub 80 spaced from thewall of an inlet boss 81 -having a supply connection 82. The interior ofthe boss 8l is in communication with the raceway 76 through a space 83between the impeller and the casing wall, so that air entering the pumpthrough the inlet may follow the arrows 85 (Fig. 8) and enter a seriesof buckets 86 disposed on the lateral face of the rotor. The space 83 isinterrupted at a chamber 87 which is formed integrally with the casingsection 73, and is adapted to maintain a liquid air separatingwhirlpool, the liquid of which engages the buckets 86 as the latter passan opening 88. This whirlpool, as in the forms previously described,serves to displace from the buckets air which enters the same throughthe pump inlet, the air entering the whirlpool and being separated fromthe water by centrifugal action. This air may pass upwardly through apassage 89 connected with the discharge connection 90, the latter beingconnected with an outlet 91, to which the raceway 76 leads, as indicatedby the arrows 92 (Fig. 7).

At the chamber 87, the space 83 between the rotor and casing wall isclosed by a close fit between the rotor and chamber wall. fit ispreferably made substantially watertight by means of complementalsealing ribs and grooves 93 upon the casing and rotor; these ribs may beused in the other forms described, if desired.

Water which is carried off from the whirlpool by means of the buckets isdischarged radially outwardly as` indicated by arrows 95 (Fig. 8) intothe raceway and from the same is discharged through the outlet 91. Sincethe outlet is in communication through passage 89 with 'the chamber 87,suflicient water will return to the chamber to maintain the whirlpool.

Due to the radial discharge of the water from the buckets in thismanner, they will return to the opening 88 filled with any air which maybe drawn through the pump inlet.

As in the form previously described, the

pump is self-priming, and is adapted to evacj uate its own supply line.Moreover, it is adapted to pump air alone; to accomplish this, it simplybeing necessary that the chamber 87 be initially supplied with sufhcientwater to maintain a whirlpool adapted to displace air from the buckets.

During liquid pumping operations, should the pump tend to become airbound. due to the This entrance of air through the inlet, the buckets u86 will begin to pump air as soon as the volnine of water in the pumpchamber decreases to a point where the buckets are not filled withwater, and after the water delivered fills the buckets, the air pumpingaction will, of course, be discontinued, since the buckets will pump aironly when the supply of water in is maintained not only by thetangential discharge from the raceway, above described, l

the supply chamber falls so low that the buckets may pick up air. v

Referring now to the form shown in Figs. 11 to 13 inclusive, the pumpcasing comprises complemental sections 96, 97, marginally securedtogether. as by bolts 98. The section 97 has an inlet boss 99 threadedas at 100, to receive a supply connection, the boss freely receiving a.hollow hub 101 of an impeller 102 carried by a shaft 103. The impellerhas cir-x cumferentially directed passages 104 of the same constructionas illustrated in Fig. 16; these passages receive fluid from they inlet,discharging the same centrifugally through peripheral openings 104 intoa raceway 105, one lateral wall 106 of which is formed on the casingsection 97, and the other wall 107 of which is formed on the casingsection 96. This raceway, which maybe of any form, preferably is of thecross sectional form illusytrated in Fig. 2, although it may take theform of the raceway shown in Fig. 10or in Fig. 8, if desired. Theraceway entrance throat 108 is relatively narrow, and of substantiallythe same width as the rotor openings 104. Radially outwardly from therotor, the raceway remains relatively narrow, being at no point ofsubstantially greater width than the rotor periphery,although it maywiden slightly, if desired, as illustrated. rIhis channel or racewayleads around the rotor, progressively increasing in radial dimensions ordepth, and discharge tangentially through an outlet 108 into a chamber109 formed integral with the casing section 97. This chamber, which isof substantially circular cross section, as in the other forms,

has set up therein, in part, at least, by the tan-- gential dischargefrom the raceway, a liquid air separating whirlpool. The air separatedby the water by the centrifugal action of the whirlpool passes outwardlythrough a discharge opening 110 threaded to receive a dischargeconnection 11. The whirlpool is principally set up by a series ofbuckets 112 which are disposed at the periphery of the rotor and on onelateral face. These buckets are formed between a circular series ofblades 113, the longitudinal direction of which is approximately radial(Fig. 11). The blades are not inclined in a direction outwardly from theface of the rotor, but may be inclined, as shown in Fig. 15.

This lateral inclinationof the blades (Fig. 15) may be also utilized inthe forms of Figs. 1 to 9 inclusive, although it will be understood thatthe blades may project at right angles from the face pf the rotor, ifdesirable.

The blades project at a right angle from one face of the rotor (Fig. 11)and are in communication with the chamber 109 through an opening 114disposed directly below the raceway outlet 108', as best `shown in Fig.11. The air separating whirlpool in the chamber but also by the actionof thebuckets as they pass the opening 114. Liquid from the whirlpoolwill pass the buckets and displace air from the whirlpool into thebuckets. This air after entering the pump inlet follows the direction ofthe arrows 116 through the space 115 between the rotor face and the wallof casing section 97 to the buckets.

As the buckets leave the chamber, into which they project as they passthe opening 114, any water carried by the buckets from the chamber isdischarged radially outwardf ly therefrom vthrough the space 116 intothe raceway 105, thus permitting the buckets to be filled with airentering the inlet before they return to the chamber. The water passesaround the raceway and is returned to the whirlpool through the outlet108. Hence, the water is being continuously returned to the whirlpoolduring an air pumpthe pump chamber contains sufficient water to fill thebuckets, the latter will not serve to pump air, but should the deliveryof the pump fall sufficiently because of air entering the same, thebuckets will immediately function, as described, to deliver the air andthus cause the pump to resume a higher capacity liquid delivery.

The pump has been found tobe highly eiicientin operating upon air alone,not only for evacuating the supply line, but for the purpose ofcompressing air, as in the forms previously described. The intakeconnection is preferably of a character which may be placed incommunication with the air whenever it is desired to pump air alone. Itwill be understood, of course, that preliminary to such an operation,the chamber 109 should first be filled with water so that there will bemaintained therein the whirlpool necessary to displace the air from thebuckets.

Referring to Figs. 14 and 15, there is shown a modified form of impellerconstruction which may be used in place of that shown in Figs. 11 and12. In. this form, the buckets do not extend to the periphery of thepumpr but are closed by means of a peripheral web 117. rlhe buckets areformed by laterally directed blades 118, the edges of which may besubstantially flush with the rotor face 119, or may project beyond thissurface, if desired. The'. buckets have bottoms 120, which are arcuatein radial planes, and as will be understood, are engaged by thewhirlpool in chamber 109 (Fig. 12) in the same manner as the buckets ofthe form shown in that ligure.

As illustrated in Fig. 15, the blades 118 may be inclined in a lateraldirection, and along. their longitudinal` edges 117 may be los exactlyradial, or if desired, disposed in planes which are substantially chordsof the rotor circumference, as shown inl m copending application, aboveymentione If desired, the rotor of all the forms described may haveassociated therewith the lateral Aadjusting means disclosed in my Patent1,686,549, October 9, 1929, and the blades thereon may be of the formshown in said patent. For purposes of description, I have referred toair and Water as the pumped iuid, but it will be understood that theseterms are used in both the description and claims to cover respectivelyany gas or liquid to be pumped..

Obviously, the .invention is not limited to the ldetails of constructionabove described, and numerous modifications may be made therein withoutdeparting from the invention. Although the general method of operationdescribed may be carried out by any of the structures, it will beunderstood that the method is not limited to the mechanical constructiondisclosed, and that various forms of pump construction may be utilizedfor practicing the same.

I claim:

l. A centrifugal pump comprising a rotor having a centrifugal discharge,a casing having an inlet adapted tointroduce fluid to the rotor inwardlyfrom its periphery, an arcuate tluid channel into which the rotordischarges, said casing having an outlet with which the channelcommunicates and through which it discharges, a series of rotatablebuckets disposed laterally of the rotor and rotatable therewith adaptedto receive air entering the pump casing, means for maintaining by theaction of said buckets a liquid whirlpool, the liquid from which engagesthe buckets and displaces their contents into the whirlpool, and meansfor leading liquid carried by the buckets from the whirlpool back to thelatter. v

2. A centrifugal pump comprising a rotor having a centrifugal discharge,a casing having an inlet adapted to introduce iiuid to the rotorinwardly from its periphery, an arcuate fluid channel into which therotor discharges, said casing having an outlet with which the channelcommunicates and through which it discharges, a series of bucketsdisposed onalateral face of said rotor, means for maintaining by theaction of said buckets a liquid whirlpool, the liquid from which engagesthe buckets and displaces the contents of the latter into the whirlpool,said bucketsbeing adapted to discharge liquid carried from the whirlpoolbefore they return to the latter, and means for returning to thewhirlpoolliquid carried therefrom by the buckets.

3. A centrifugal pump comprising a rotor having a centrifugal discharge,a casing having an inlet adapted to introduce fluid to the rotorinwardly from its periphery, an arcupool, and means for receiving fromthe buckets and returning to the whirlpool liquid carried therefrom bythe buckets.

4. A centrifugal pump comprising a rotor having a series of passagesleading toward its periphery, a casing having an inlet adapted tointroduce fluid to the rotor inwardly from its periphery, an arcuatefluid channel into which the rotor discharges, said casing having anoutlet with which the channel communicates and through which itdischarges, a series of buckets on the rotor adapted to receive air,means for maintaining by the action of said buckets a liquid whirlpool,the liquid from which engages the buckets and displaces the contents ofthe latter ito the Whirlpool, and means for leading directly to saidchannel liquid carried from the whirlpool by the buckets, said Whirlpoolmaintaining means being in communication with said channel.

5. A centrifugal pump comprisng a rotor having a centrifugal discharge,a casing having an inlet adapted to introduce Huid to the rotor inwardlyfrom its periphery, anarcuate `Huid channel into which the rotorcentrifugally discharges, said casing having an outlet with which thechannel communicates and through which it discharges, a series ofrotatable buckets disposed laterally of the rotor and rotatabletherewith adapted to receive air entering the pump, means formaintaining by the action of said buckets a liquid whirlpool, the liquidfrom which engages the buckets and displaces the contents of the latterinto the whirlpool, and means for directing to the channel liquidcarried by the buckets from the whirlpool, said whirlpool maintainingmeans being in communication with said channel through said outletwhereby the liquid is returned to the whirlpool.

6. A centrifugal pump comprising a rotor having a series of passagesleading toward its periphery, a. casing having an inlet adapted tointroduce fluid to the rotor inwardly from its periphery, an arcuateHuid channel into which the rotor discharges, said casing having anoutlet with which the channel communicates and through which itdischarges, a series of buckets adapted to receive air disposed on alateral face of said rotor, means for maintaining by the action of saidbuckets a liquid whirlpool, the liquid from which engages the bucketsand displaces the contents of the latter into the whirlpool, and meansfor directing back to the Whirlpool liquid carried periphery, a casinghaving an inlet adapted to introduce fluid to the rotor inwardly fromits periphery, an arcuate fluid channel into which the rotor discharges,said casing having an outlet with which the channel comm municates andthrough which it discharges, a

series of buckets adapted to receive air independently of said passagesand disposed on a lateral face of said rotor, means for maintaining bythe action of said buckets a liquid l5 whirlpool, the liquid from whichengages the buckets and displaces the contents of the latter into theWhirlpool, and means for directing-back to the whirlpool liquid carriedtherefrom by the buckets, said means including said channel.

8. A centrifugal pump comprising a rotor having a series of passagesleading toward its periphery, a casing having an inlet adapted tointroduce fluid to the rotor inwardly from its periphery, an arcuatefluid channel into which the rotor discharges fronrits periphi ery, saidcasing having an outlet with which the channel communicates and throughwhich it discharges, a series of buckets adapted to 3o receive airthroughsa-id inlet, means for maintaining by the action of said bucketsa liquid whirlpool, the liquid from which engages the buckets anddisplaces the contents of the latter into the whirlpool, and means;,independent of the buckets for returning to the whirlpool liquidcarried therefrom by the buckets. g

9. In a pump, a rotor having a centrifugal discharge, a casing having aninlet adapted t ,0 introduce fluid into said rotor inwardly from itsperiphery and having a iuid channel around the rotor to receive thefluid impelled thereby, said casing also having an outlet openingleading from said channel, a disa charge connection in communicationwith said outlet opening, a series of buckets rotatable simultaneouslyivith the rotor in communication with an air inlet, a chamber formaintaining by the action of the rotor a liquid air separating whirlpoolwhich engages the buckets and causes introduction of air into thewhirlpool from the buckets, the chamber being in communication with thebuckets through an openingin the chamber .'15 wall, and meansindependent of the buckets for returning to the chamber liquid which iscarried from the Whirlpool in the buckets.

.10. In a pump, a rotor having a centrifugal discharge, a casing havingan inlet adapted to 6U introduce fluid into said rotor inwardly from itsperiphery and having a fluid channel to receive the fluid peripherallyimpelled thereby, sald casing also having an outlet opening leading fromsaid channel, a discharge connection in communication with said outletopening, a series of buckets on said rotor opening laterally therefromand in communication with an air inlet, a chamber for maintaining by theaction of the rotor a liquid air separating Whirlpool which engages thebuckets and causes introduction of air from the buckets into thewhirlpool from the buckets, the chamber being in communication with thebuckets through an opening in the chamber Wall, means for permittingdischarge from the buckets into said channel, there being acommunication between the channel and said chamber whereby liquidcarried od by the buckets from the whirlpool is returned to the latter.

11. The method of operating a centrifugall pump having a centrifugallydischarging rotor and air carrying buckets which comprises maintainingin communication with the air carrying buckets a body of liquid, set--ting up in said body by the rotor action an air separating/Whirlpool,utilizing the whirling action of said body to displace air into thewhirlpool-from the buckets, and returning to the whirlpool by meansother than the buckets the air displacing liquid which is carried fromthe 'whirlpool by the rotor buckets.

12. The method of operating a centrifugal pump having a centrifugallydischarging rotor and air carrying buckets which comprises maintainingin communication with the air carrying buckets a body of liquid, settingup in said body by the rotor action an air separating Whirlpool,utilizing the whirling action of said body to displace air into thewhirlpool from the buckets, and returning the liquid carried from thewhirlpool by the rotor buckets to a part of the Whirlpool other thanthat engaged by the buckets. y

13. The method of operating a centrifugal pump having a centrifugallydischarging ICI) rotor and air carrying buckets which comprisesmaintaining in communication with the air carrying buckets a body ofliquid, setting up in said body by the rotor action an air separatingwhirlpool, utilizing the whirling action of said body to displace airinto the whirlpoolfrom the buckets, returning to the Whirlpool the airdisplacing liquid whichis carried from the Whirlpool by the rotorbuckets before the same return to the whirlpool and re-introducing theliquid into the whirlpool through a passage independentof the bucketscommunicating therewith.

14. The method of operating a centrifugal pump having a main dischargeoutlet which comprises maintaining a portion of the pumped liquidadjacent the rotor, setting up by the action of the rotor at a pointseparate from said outlet, but in communication there-` With, a liquidair separating whirlpool, utilizing the whirling action of said liquidto dlsplace air from the rotor into the whirlpool buckets by dischargingthe liquid from the at a point other than said outlet, discharging theseparated air from the whirlpool and returning to the whirlpool throughsaid outv' let liquid carried therefrom by the rotor.

15. The method of operating a centrifugal pump having a main dischargeoutlet which comprises maintaining a portion of the.

pumped liquid adjacent the rotor, setting up bythe action of the rotorat a point separate from said outlet a liquid air separating whirlpool,utilizing the whirling action of said liquid to displace air from therotor into the whirlpool at a point other than said outlet, dischargingfrom the whirlpool-engaging portion water carried thereby from thewhirlpool, whereby said portion may return to the whirlpool freed ofwater, taking up air in said portion, and returning said dischargedwater to the whirlpool.

16. The method of operating a centrifugal pump having a raceway and amain discharge outlet leading therefrom, and a rotor adapted todischarge centrifugally into said raceway, which comprises maintaining aportion of the pumped liquid adjacent the rotor, setting up by theaction of the rotor at a point separate from said outlet and radiallyinwardly from the raceway,l a liquid air separating whirlpool, utilizingthe whirling action of said liquid to displace air from the rotor intothe whirlpool at a point other than said outlet, discharging from thewhirlpool-engaging portion into the raceway water carried therey fromthe Whirlpool, whereby said portion may return to the whirlpool freed ofwater, taking up air in said portion, and returning said dischargedwater to the whirlpool.

In testimony whereof I have hereunto se my hand. I

ARTHUR W. BURKS.

y 1,867,652lr

